Process of producing nitrogen simultaneously with oxids of nitrogen.



burrs srx rns PATENT ormcn MARTINROHMER, or eERsrI-IoFEN, NEAR AUGSIBURG, GERMANY, AssrGNon T0 FARBWERKE VOBM. MEISTEB LUoIUS & BRUNING, OF HooHsT-oN-THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

,PROCESS OF PRODUCING NITROGEN SIMULTANEOUSLY WITH OXIDS 0F NITROGEN.

No Drawing.

To all whom it may concern:

Be it known that I, MARTIN ROHMER, Ph. D., chemist, a citizen of the Empire of Germany, residing at Gersthofen, near Augsburg, Germany, have invented certain new and useful Improvements in Processes of Producing Nitrogen Simultaneously with Oxids of Nitrogen, of which the following is a specification.

In U. S. Patent 1,096,392 patented May 12, 1914, I have described a process for producing nitrogen simultaneously with oxids of nitrogen by burning ammonia in atmospheric air, the characteristic feature of which is that there is no excess of oxygen in the reacting mixture of air and ammonia of high concentration, so that, after the separation of lower or higher oxids of nitrogen, pure atmospheric nitrogen is obtained.

In the course of my further researches on the subject-matter of the above invention, I have found that there may also be used combustion air with a higher percentage of oxygen than corresponds to atmospheric air while maintaining the same proportion o ammonia andoxygen as is essential in the process described in the aforesaid patent.

This process ofi'ers some particular advantages if it is intended to obtain the oxids of nitrogen, which are produced simultaneously with atmospheric nitrogen, in concentrations which are still higher than in the aforesaid patent.

For instance the proportion stated in Example H of that patent, viz. 12.3 parts by volume of ammonia-gas; to the oxygen contained in 87.7 parts by volume of air, may also be obtained by substituting for this air oxygen in any desired degree. In this case the limit of the proportion is 2 parts by volume of ammonia gas to 3 parts by volume of oxygen. Such gas-mixture is of an explosive character; however by replacing only about half of the combustion air by oxygen any danger of explosion is removed as it is, for instance, when using a mixture of 12.3 parts by volume of ammonia-gas Specification of Letters Patent.

Patented Jana 15, 1918..

Application filed April 16, 1914:. Serial No. 832,236.

and only 40 parts by volume of air and 10 parts by volume of oxygen or, what amounts to the same, parts by volume of an air richer in oxygen and containing 36.8 per cent. of oxygen. By substituting oxygen for the air to a still greater extent and thus increasing the percentage of oxygen, the mixture of ammonia, air and oxygen be: comes inflammable and precautions must be taken to prevent the flame from being thrown back into the mixing vessels.

When a mixture of the above proportion of ammonia to oxygen is burned, nitric oxid (NO) is obtained in a very good yield and an extremely hi h concentration. After cooling, the quantlty of the residual oxygen is suflicient only for the conversion of one half of the nitric oxid (N0) into nitrogen tetroxid. lFhus, a mixture of nitric oxid (NO) and nitrogen tetroxid (N 0,) is pro duced, which mixture, when further cooled, forms nitrogen trioxid (N 0 By absorption in caustic soda lye, the latter is most easily and completely converted into the valuable sodium nitrite, and the escaping gases will be pure atmospheric nitrogen.

The present process may, of course, be carried out also with a higher pressure. Then, the roportion of ammonia to oxygen being for instance two volumes of ammonia gas to three and a half volumes of oxygen, there is directly obtained, without stron 0" refrigeration, nitrogen tetroxid in liquid condition, since in this case the oxygen remaining after the combustion of the ammonia secondarily oxidizes the whole of the nitric oxid, as described in the aforesaid Patent No. 1,096,392, Example I, and the modification thereof accordlng to Example IV;

Having now described my invention what I claim is:

1. The process of producing nitrogen and oxids of nitrogen, which conslsts in burning ammonia in presence of oxygen and nitrogen, the proportion of oxygen nitrogen being higher than in atmospheric air, the

reaction mixture containing a high percentjecting said mixture to the action of a hot 10 age of ammonia, and ust sufiioient oxygen catalyzer, substantially as described. to oxidize the hydrogen-component of the In testimony whereof I afiix my signature ammonia 1to Water aid its dnitrogen-cornin presence of two witnesses.

onent to oWer or big er oxi s of nitrogen. p 2. The process of producing nitrous gases MARTIN ROHMER which consists in providing a mixture of Witnesses: oxygen, air and ammonia containing suifi- A. V. W. COT'I'ER, cient oxygen to sustain the reaction, and sub- W. ROEDER. 

